#! /bin/zsh
#
# this file:
#   https://dataswamp.org/~incal/conf/.zsh/mail
#
# DMARC issue:
#   https://en.wikipedia.org/wiki/DMARC
#   https://mailarchive.ietf.org/arch/msg/ietf/kL24edUthAOuHuwK3ZnpFkCXduI
#
# discussion and commands:
#   http://lists.gnu.org/archive/html/help-gnu-emacs/2019-05/msg00476.html
#   http://lists.gnu.org/archive/html/help-gnu-emacs/2019-05/msg00477.html
#   http://lists.gnu.org/archive/html/help-gnu-emacs/2019-05/msg00481.html
#
# (rfc 7489)
#   "Domain-based Message Authentication, Reporting, and Conformance (DMARC)"
#   <https://datatracker.ietf.org/doc/html/rfc7489>
#
# (rfc 8616)
#   "Email Authentication for Internationalized Mail"
#   <https://datatracker.ietf.org/doc/html/rfc8616>

DMARK_ZOHO=_dmarc.zoho.eu

dig-zoho () {
    dig $DMARK_ZOHO txt +short
}

host-zoho () {
    host -t txt $DMARK_ZOHO
}

test-zoho () {
    local server=pop.zoho.com
    local port=995
    local server_port=${server}:${port}

    echo "socat"
    socat - OPENSSL:${server_port}

    echo "\nopenssl"
    openssl s_client -quiet -connect $server_port

    echo "\ngutls-cli"
    gnutls-cli --port $port $server
}